Ibe Calendars and Chronology 15 That EgTpt and the peoples of the Mediterranean islands shared a common knowledge of astronomy has been established. Equally it can be shown that they shared to some extent a common metrology. That science should follow the trade routes was only natural; but we cannot tell in which direction science flowed along these routes. Much information on that matter may well lie buried beneath the Nile silt accumulated in the Delta during the passage of the last fifty centuries. Even, however, if that is unearthed, it is improbable that it will enable scholars to determine the origin of this science which admittedly appears to accord little with the picture, as we see it, of the cultural development of the peoples of the epoch of Menes. It may be, as some indeed suspect, that the science which we see at the dawn of recorded history was not science at its dawn but represents the remnants of the science of some great and as yet untraced civilization. Where, however, is the seat of that civilization to be located ? The Assyriologist traces the culture of Sumer back towards Central Asia, properly preferring the tangible evidence to the legends of Sumer. Central Asia, however, is not a happy source for navigational science. We must look elsewhere for that. Some students of the ancient civilizations of America, coupling the evidence found in that continent with the mythologies of Greece and of Egypt, place it beneath the waves of the Atlantic Ocean: there the problem may appropriately be left. J. W, S. SEWELL failed to show how the stars were used to give a bearing during 18 hours of the 24 in the latitudes of Britain in summer.